Julia Gillard has declared Labor's leadership ructions "completely at an end" after being elected unopposed as leader following a farcical Caucus leadership spill.

Labor once again revealed its deep internal divisions as the spill, called for 4:30pm AEDT, fizzled out following former PM Kevin Rudd's announcement that he would not run.

The Prime Minister was duly re-elected unopposed and unanimously, along with her Deputy Wayne Swan.

The spill was called after a dramatic intervention from party elder Simon Crean, who demanded the leadership be put to a vote to end the "disunity" which he said was killing the party.

Speaking after the Government withdrew its contentious media reform bills because they had failed to attract enough support in the House of Representatives, Mr Crean had called on Mr Rudd to show his hand and stand against the PM.

"I don't want any more games, I'm sick to death of it, it's about time he stood up and instead of having his camp leak things, actually have the courage of his conviction and his belief," Mr Crean said.

But just 10 minutes before the ballot, Mr Rudd said he would not dishonour his previous promises not to stand.

Look back at how the day unfolded using our live blog (All times AEDT):

I can't understand why all of this agitation would be on, including the need to bring it to a head then for the pretender not to stump up. So that was - he should have run. There is no question about that, Leigh, he should have run. I think that itself would have been an important cleansing, I suppose, for the party.

Mr Crean says he has no regrets about bringing the tensions to a head today:

I don't have have any regrets about the path that I took because I did it out of no personal gain, out of no animosity to Julia, who I go back a long time with. It meant me having to put my differences aside with Kevin, but also pledging that in the healing process, that I wanted to be part of the exercise that demonstrated the very point that you were just asking me about, that we could actually he heal, that we could actually come together, settle our difference in the interests of unifying the show. If that result didn't work, the one thing the Labor Party must now do is to unify around the result they got.

He finishes with a plea to the party, who he says are capable of putting their best foot forward and "inspiring a nation" again in the vein of the Hawke and Keating years.

We remind people of what our brand really is. We don't have to invent our brand. At the moment we are doing a lot to take people's minds off what it was. We don't have to reinvent it, we have to reinforce it, rebuild it and present a positive image going forward.

7:06pm: Moments ago we received this statement from one of the Prime Minister's spokesmen:

"The Prime Minister has received the resignation of the Member for Corio, the Honourable Richard Marles, as Parliamentary Secretary for Pacific Island Affairs and as Parliamentary Secretary for Foreign Affairs. The Prime Minister has accepted the resignation. The Prime Minister thanked Mr Marles for his contribution and service, and acknowledges his behaviour in offering his resignation is honourable."

He served as parliamentary secretary for foreign affairs and Pacific island affairs.

6:28pm: Greens leader Christine Milne says the Labor Party is a complete shambles.

She says, however, that her party still wants to work with the Government.

"We are calling on the Labor Party backroom boys for goodness sake get out of the way and let this Parliament deliver the good things that the country want.

"The minority Government hasn't failed. Labor has failed. Let me put that very strongly."

6:16pm: The dramatic events of this afternoon have been described by the independent Member for New England, Tony Windsor, as sad to watch.

"It's the Clayton's ballot. It's the ballot you have when you're not having a ballot.

"So the status quo remains. Maybe that was part of what Simon Crean was trying to do, to clear the air, but it's a fairly ordinary look."

6.03pm: Defence Minister Stephen Smith says a number of people need to reconsider their positions after today.

Mr Smith said Joel Fitzgibbon, a known Rudd backer, has already flagged that he will consider his role as chief whip.

"And that is appropriate and that is right.

"And he's not in my view the only one who needs to consider his or her position.

"(Julia Gillard) was elected unopposed today by a Caucus of about 100... It's over. That's it. Finished.

"In my experience, when you have weeks of hints and suggestions in the end when there's a nil contest, that's because the challenger doesn't have a sufficient pile of votes."

5:39pm: It's hard to say what the Labor Government has gained from today's events, if anything at all.

Despite declarations that this is over once and for all, Federal Labor has revealed its deep internal divisions once again.

Julia Gillard is still Prime Minister, but this is hardly likely to give Labor a lift in the polls.

On a day when crowds gathered for an apology to the victims of forced adoptions, and the day after the National Disability Insurance Scheme passed Parliament, valuable hours were devoted to this issue by MPs and the press corps.

5:32pm: Tony Abbott is responding to what he says is a "very big day". He says Andrew Wilkie, Rob Oakeshott, and Tony Windsor all voted with the Coalition in support of today's failed no confidence motion, and calls for the election date to be brought forward.

"The message that the people of Australia have received from this Government is that nothing is resolved, the civil war goes on.

"The civil war will continue as long as Kevin Rudd and Julia Gillard are in the Parliament.

"The only way to give our country the good government so that we so badly need right now, at a difficult time in the life of our nation, is to have an election.

"We cannot wait till September 14. If the Prime Minister was concerned about the party, if she was concerned about the country, if she was less concerned about herself and her own survival, there would be an election now."

5:31pm: Here's video of Julia Gillard and Joel Fitzgibbon speaking after the spill.

Annabel Crabb says many Australians would be feeling disappointed the speech was overshadowed.

"The people who are directly interested in that apology have every right to feel a bit let down, a lot let down, disappointed saddened by what's happened," she said.

"But more generally, I think that over recent months and even years the Australian public in general has become very disenchanted with politics and politicians arguing who's going to do which job and quibbling over their entitlements as office bearers rather than doing the business of the Parliament."

5:11pm: Chris Uhlmann declares that today's drama has been an "utter farce".

"When we saw Simon Crean this morning there appeared to be some coordination in this. It all ended up as a damp squib today ... It's hard to put aside the sense that what we've seen today has been an utter farce."

While for Annabel Crabb it's "been like a piece of performance art" conducted by "genuinely confused people".

"That's what I thought when I listened to Simon Crean's press conference. It seemed to be an opening act without much of a conclusion. And it's ended in kind of farce I suppose.

"I think that often the criticism is made of politics that it's very packaged and stage-managed and very slick. I think what you've seen here is kind of a live theatre of one kind or other.

"I think that this whole circumstance in the federal Labor Party is one that's composed of genuinely confused people.

"I think Simon Crean started something today that he thought would finish one way and it didn't finish that way at all."

"Well, I think that she's had an enormous amount of pressure put on her. It's the amount of pressure that would really crack almost any living breathing human being.

"I must say that when she opened Question Time with the words, you know: 'Simon Crean will be represented by Anthony Albanese, there will be a ballot at 4:30pm. Until then, give it your best shot,' I mean, I did reflect that she is an incredibly tough individual."

4:57pm:

Text from Labor source 'just another day in the Gillard Govt.' (May have included a WTF) #nospill#spillfail

4:43pm: As it stands, there is a leadership spill without a contender.

In a stunning development, Kevin Rudd has said he will not stand for the leadership in this afternoon's caucus ballot.

There's still the chance a third person will nominate.

But in every likelihood Returning Officer Chris Hayes will emerge within the next half hour or so, to report that the position of leader was thrown open, Julia Gillard was the only one to nominate and was therefore re-elected unopposed.

As far as the Deputy PM position goes, we know Simon Crean has said he will put his hand up against Wayne Swan. But without a "running mate" even that is now in doubt.

Or, to put it another way...

This really must go down as one of the least successful games of "Simon Says" ever. #spill

"I believe in honouring my word... others take such commitments lightly, I do not.

"I have been very plain about that for a long period of time.

"Secondly, I have also said that the only circumstances under which I would consider a return to leadership would be if there was an overwhelming majority of the parliamentary party requesting such a return, drafting me to return and the position was vacant.

"I am here to inform you that those circumstances do not exist.

"Therefore, in the absence of any such draft not withstanding what Simon Crean had to say this morning, I will be adhering absolutely to the commitment that I gave the Australian people and to my parliamentary colleagues.

"This is a difficult day for the Australian Labor Party, it is a difficult day for is a Australian government, but I take my word seriously.

"I have given that word. I gave it solemnly in that room after the last ballot and I will adhere to that word today. I therefore suggest to all and sundry across the party and the Government that we unite in ensuring that Tony Abbott does not simply walk into the Lodge as if it is his own personal property.

"We are a government with a proud record. Health and education, the economy, it is a record upon which we should robustly stand.

"But I'm not prepared to dishonour my word which I gave solemnly. I will, therefore, adhere to that word as I have said before and excuse me I'm going to Caucus."

He said some time ago he felt Kevin Rudd was disloyal. He mocked and ridiculed him at one point.

Even at his news conference today [he said]: 'I don't want any more games. I'm sick of it. It is about time he - that is Kevin Rudd - stood up and instead of having his camp leak things... has the courage of his convictions and his beliefs'.

This is the guy who says he will support Kevin Rudd and wants to be his deputy. What is the public to make of this? There is no unity here, not even between the intended leader Kevin Rudd and this guy who wants to be his deputy, Simon Crean.

3:33pm:

ABC 7.30's political editor Chris Uhlmann tells ABC News24 that today's Labor crisis is a "foot soldiers' revolt" as opposed to the initial Rudd-Gillard spill which he called a "Generals' revolt":

"It happened in the dead of night. Very few people were aware of it. Most of them were made aware by the broadcast on the ABC. I had people ringing me that night asking me what was going on - Cabinet ministers who'd been left out of the loop."

3:20pm:

As I said yesterday, @juliagillard is as tough as they make them- she'll win today & on 14 Sept because she’s got the reforms for the future

The ABC's Lyndal Curtis says we still do not know if there will be a challenger in this afternoon's leadership ballot.

"Before that though, Julia Gillard has to survive parliamentary votes in the House. The Coalition has 72 votes with the Liberal Party and the National Party.

"It needs another four votes to get to 76, to get to the magic number to allow it to suspend standing orders to allow the Opposition Leader to move a no-confidence motion."

2:35pm:

Speaker says a division is required.

2:32pm:

Julia Gillard responds to Tony Abbott calling a motion of no confidence in the Government:

"What we've seen across the contributions of the leader and the deputy leader of the Opposition is the same negative dummy spit that they've been engaged in since the 2010 election.

The Leader of the Opposition just had an opportunity to indicate to the Australian people if he chose to take it what his vision was for the country, what his vision is and what his leadership attributes are. Instead, because he is unable to do that, he filled the space with the only thing he knows how to do is that is negativity, bitterness and the politics of personal assault."

1:42pm: If there is a leadership spill, it will be the third in just three years for the Labor government. Mr Rudd lost the last leadership challenge which he launched in February 2012.

1:40pm: Simon Crean's former chief of staff Simon Banks says Mr Crean is a "compromise" candidate in the deputy role.

"Well, clearly he is putting himself up in that deputy's role as a compromise candidate between the two camps, hoping that might act as a bridge to some kind of resolution to these issues as well. I guess we have to see how his Caucus colleagues react to that."

1:35pm: Lyndal Curtis tells ABC News 24:

"We don't yet know if Kevin Rudd has been convinced to stand.

"He would need to be convinced to stand to go against what he has said consistently since February last year.

"There may be some levels of confidence among his supporters that he stands. I don't know. You don't usually get these opportunities presented to you often if you want to be leader, and you tend to take them when you get them. These decisions have not been made yet."

1:30pm: Sam Dastyari has hit Twitter to deny ordering the NSW Right to turn on Gillard.

Check your facts mate. I vehemently oppose those outside the caucus making these decisions.“@phillipcoorey: NSW Right boss Dastyari..... "

1:25pm: Simon Crean commenting on whether his actions will affect the current deal with the independent MPs:

"The fact is I've had the responsibility for dealing with the agreement with the independents for over three years.

"We've delivered on every front. I certainly have no intention of tearing up that agreement.

"I think that's a question, at the appropriate time, you would need to direct to the independents, but I think there is no point continuing on in a hung parliament in these circumstances, and it is better for us to resolve the circumstances we can control rather than try and predict those we can't."

When asked whether he had lost confidence in Wayne Swan and whether Anthony Albanese should be the one to serve as a deputy to Mr Rudd, Mr Crean replied: "It is a matter for Caucus."

1:20pm: Fairfax's Phil Coorey has tweeted that NSW Right boss Sam Dastyari has ordered the faction to unite against Julia Gillard.

1:16pm: Crean is still speaking:"There is no ticket between me and Kevin. Let's get that right. I am not saying I am only doing this if he nominates me as his deputy."

1:15pm: Simon Crean said the Prime Minister's reaction was to say that she would not be calling for a spill:

"Now, I urged her in the circumstances to reconsider that.

"I understand if she does not, but if it is the case and we are to end this, then the Caucus has other options, but it has to do them, and it must do it if we are to resolve this position expeditiously."

1:13pm: Crean says he has not spoken to Kevin Rudd in the last 48 hours.

"I have had discussions in not just recent weeks with him, those discussions started from policy perspectives, but we clearly had discussions.

"And it was important in arriving at this decision that I was convinced he was going to be, what I've called on other occasions, a 'changed Kevin' or a more disciplined asset.

"Now, I'm satisfied with the responses that I've had, but I believe it's important that he is continued to be held to it, and that's why I've put my name forward for the deputy position."

1:12pm More:

"He [Rudd] has got no option but to run. I don't want any more games, I'm sick to death of it, it's about time he stood up and instead of having his camp leak things, actually have the courage of his conviction and his belief.

"I'm urging Mr Rudd to put his name forward, in the interests of breaking the deadlock, but I do not believe that simply changing to Mr Rudd from Ms Gillard is going to solve our problems.

"The internals have to stop. We have to get on with the message and it has to become an inclusive party."

1:09pm: Crean says he won't stand for the leadership, but will offer himself up as deputy.

"Kevin Rudd in my view has no alternative but to stand for the leadership.

"He can't continue to play the game that he's reluctant or must be drafted.

"I know he won't be drafted.

"That's why I'm putting myself forward as part of the leadership group."

1:05pm: "Kevin Rudd, in my view, has no alternative but to stand for the leadership. He can't continue to play the game that says he is reluctant or he has to be drafted."

1:00pm: Crean: "The party through the Government is in a stalemate position. Something needs to be done to break this deadlock."